Q98 / 180 · NEET 2026 (Re-NEET) · Chemistry
Match the species in List I with their geometry in List II
List I List II A. PCl$_5$ I. Tetrahedral B. BrF$_5$ II. Square Planar C. BF$_4^-$ III. Trigonal bipyramidal D. [Ni(CN)$_4$]$^{2-}$ IV. Square pyramidal
Choose the correct answer from the options given below:
| List I | List II |
|---|---|
| A. PCl$_5$ | I. Tetrahedral |
| B. BrF$_5$ | II. Square Planar |
| C. BF$_4^-$ | III. Trigonal bipyramidal |
| D. [Ni(CN)$_4$]$^{2-}$ | IV. Square pyramidal |
- AA-III, B-II, C-I, D-IV
- BA-IV, B-III, C-I, D-II
- Correct answerCA-III, B-IV, C-I, D-II
- DA-III, B-I, C-II, D-IV
Solution
For $\text{PCl}_5$, the central atom $\text{P}$ has $5$ valence electrons. It forms $5$ bond pairs with $\text{Cl}$ atoms and has $0$ lone pairs. The hybridization is $sp^3d$, and the geometry is trigonal bipyramidal. (A $\rightarrow$ III)
For $\text{BrF}_5$, the central atom $\text{Br}$ has $7$ valence electrons. It forms $5$ bond pairs with $\text{F}$ atoms and has $1$ lone pair. The hybridization is $sp^3d^2$, and the geometry is square pyramidal. (B $\rightarrow$ IV)
For $\text{BF}_4^-$, the central atom $\text{B}$ has $3$ valence electrons plus $1$ from the negative charge, giving $4$ electrons. It forms $4$ bond pairs with $\text{F}$ atoms and has $0$ lone pairs. The hybridization is $sp^3$, and the geometry is tetrahedral. (C $\rightarrow$ I)
For $[\text{Ni}(\text{CN})_4]^{2-}$, the central metal ion $\text{Ni}^{2+}$ has a $3d^8$ electronic configuration. Since $\text{CN}^-$ is a strong field ligand, it causes the pairing of electrons in the $3d$ orbitals. The hybridization is $dsp^2$, and the geometry is square planar. (D $\rightarrow$ II)
The correct matching is A-III, B-IV, C-I, D-II.
Answer: A-III, B-IV, C-I, D-II
For $\text{BrF}_5$, the central atom $\text{Br}$ has $7$ valence electrons. It forms $5$ bond pairs with $\text{F}$ atoms and has $1$ lone pair. The hybridization is $sp^3d^2$, and the geometry is square pyramidal. (B $\rightarrow$ IV)
For $\text{BF}_4^-$, the central atom $\text{B}$ has $3$ valence electrons plus $1$ from the negative charge, giving $4$ electrons. It forms $4$ bond pairs with $\text{F}$ atoms and has $0$ lone pairs. The hybridization is $sp^3$, and the geometry is tetrahedral. (C $\rightarrow$ I)
For $[\text{Ni}(\text{CN})_4]^{2-}$, the central metal ion $\text{Ni}^{2+}$ has a $3d^8$ electronic configuration. Since $\text{CN}^-$ is a strong field ligand, it causes the pairing of electrons in the $3d$ orbitals. The hybridization is $dsp^2$, and the geometry is square planar. (D $\rightarrow$ II)
The correct matching is A-III, B-IV, C-I, D-II.
Answer: A-III, B-IV, C-I, D-II
Hence, the correct answer is option: 'C'.